Ultrasonic testing (UT) is a family of non-destructive testing techniques based on the propagation of ultrasonic waves in the object or material tested. In most common UT applications, very short ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz, and occasionally up to 50 MHz, are transmitted into materials to detect internal flaws or to characterize materials. A common example is ultrasonic thickness measurement, which tests the thickness of a targeted object to determine the thickness of the object. Pipeline walls are routinely measured in this manner from the exterior of the pipeline to check for internal laminations and wall loss (corrosion and erosion)
Ultrasonic testing is often performed on steel and other metals and alloys, though it can also be used on concrete, wood and composites, albeit with less resolution. It is used in many industries including steel and aluminum construction, metallurgy, manufacturing, aerospace, automotive and other transportation sectors.
In ultrasonic testing, an ultrasound transducer connected to a diagnostic machine is passed over the object being inspected. The transducer is typically separated from the test object by a “couplant” such as oil or water. Phased array ultrasonics (PA) is an advanced method of ultrasonic testing that has applications in medical imaging and industrial nondestructive testing. Common industrial applications are noninvasive examination of manufactured materials such as welds joining large sections of pipes or steel decking for bridges.
Ultrasonic testers are typically separated into two classes of devices. Single-element (non-phased array) probes, known technically as monolithic probes, emit a beam in a fixed direction. To test or interrogate a large volume of material, a single-element probe must be physically scanned (moved or turned) to pass or traverse the beam through the area of interest. In contrast, the beam from a phased array probe can be focused and swept electronically without moving the probe. The beam is controllable because a phased array probe is made up of multiple small elements, each of which can be pulsed individually at a computer-calculated timing. The term “phased” refers to the timing, and the term “array” refers to the multiple elements. Phased array ultrasonic testing or “PAUT” is based on principles of wave physics, which also have applications in fields such as optics and electromagnetic antennae.
In the non-destructive testing of material and welds, the phased array probe emits a series of beams to flood the weld with sound and a flaw can be seen or “read” on a display screen attached to the phased array ultrasonic tester, usually highlighting a weld “indication” or potential flaw as a colored indication on the instrument display screen.
There are two main methods of receiving the ultrasound waveform: reflection and attenuation. In reflection mode sometimes referred to as “pulse-echo” mode, the transducer performs both the sending and the receiving of the pulsed waves as the “sound” is reflected back to the device. Reflected ultrasound comes from an interface, such as the back wall of an object, geometry reflections, or other foreign objects or from an imperfection within the object such as a weld defect. The diagnostic machine displays these results in the form of a signal with an amplitude representing the intensity of the reflection and the distance, representing the arrival time of the reflection. In attenuation mode sometimes referred to as “through-transmission” mode, a transmitter sends ultrasound through one surface, and a separate receiver detects the amount that has reached it on another surface after traveling through the medium. Imperfections or other conditions in the space between the transmitter and receiver reduce the amount of sound transmitted, thus revealing their presence. However, as is known, couplants are needed to provide effective transfer of ultrasonic wave energy between the transducer probes and the objects being inspected to reduce or eliminate the attenuation from air to ensure enough ultrasonic energy is present inside the object so a useable ultrasonic response can be obtained.
For the testing of materials and in particular for the testing of welds, the pulse-echo method is preferred and various PAUT devices are offered in the non-destructive testing industry for such testing. For example, Olympus Scientific Solutions Americas Inc., (aka Olympus NDT) based in Waltham, Mass., offers a product under the name OmniScan/OmniPC which may be used to test steel structures for determining inspection compliance. Using such a product is often referred to as “scanning” a weld and such testing produces “scan data” representing the area tested which can be read back and reviewed at a time of choosing by an inspector. Such captured scan data can be saved in common data storage systems, such as cloud-based storage, and retrieved at any time for review using known PC based systems. Further, later and evolving systems can access such weld scan data and assist in the identification of potential weld defects by removing nominal or non-suspect scan data to lessen the amount of time required for an inspector to review the data and to focus attention on suspected areas that may represent a potential weld flaw.
A suitable procedure for taking scans, recording those scans, and then analyzing the scans to reduce the examination burden for the inspector is found in U.S. patent application Ser. No. 14/986,195, pages 7-22, and all referenced figures, all of which are hereby incorporated by reference. In association with standard ultrasonic weld analysis techniques, and using the procedure disclosed in the above referenced application for determining ultrasonic reflection amplitudes (i.e. “voxels”), weld seams may be non-destructively tested to determine code or procedural compliance. Further discussion regarding the use of a PAUT system, understanding the testing procedures for welds using such a system, the reading of a PAUT display, the reading of a display produced by an associated PC application to view testing data, and how to calculate the distances and dimensions provided by such a testing application shall not be provided as such information is either well understood or fully disclosed in the above referenced application, or not necessary for a complete and full understanding of the herein described invention.
However, such UT data processing (also referred to herein as UT data analyzer or a UT data analyzation) as described in the above referenced application, irrespective of the sophistication of a PAUT device used to capture the data, may be of little usefulness if the inspector has not correctly configured the system prior to or during testing of the targeted weld area, even if the scanning was done with automated motorized scanners. Phased array inspectors must be trained and certified in the use of PAUT systems, their settings and limitations, and well understand the materials being targeted by the PAUT device for scanning, and the operator must be vigilant to configure the testing device correctly in order to obtain valid scan results. If a device is incorrectly configured, the UT data processing will not assist the examiner and, worse, may delay the discovery of a flawed data file until that data file is well past data processing when access to the tested area may be difficult or impossible in an ongoing construction environment.
As will be understood, the arrangement, scheduling, and organization of testing of welds in a construction project are complicated in their own right, and the rescanning of a weld area to produce a valid scan data file may cause costly delays in a construction project, or even interfere with other scheduled processes causing cascading schedule delays. Moreover, an inspector may spend a great deal of time reviewing scan data only to discover during their data inspection that the captured data itself is flawed and not usable for their code or procedural compliance objectives, sometimes causing confusion as to the source of the data capture flaw causing even more lost time to determine the source of the scanning error. Hence, the incorrect configuration of a testing device by a PAUT inspector can cause confusion and cost in a construction project.
Therefore, what is needed is a method for determining at the earliest point possible after the creation of a scan data file, but at least prior to any further data processing used by a weld inspector for weld examination, whether such data is valid or flawed so that file or scan remediation may occur.